The present invention is directed to a two-way wireless communication system for linking the elements of an HVAC or building automation system. For purposes of this application, an HVAC system is an assembly of physically distinct, diverse elements operating together to accomplish heating, cooling and/or air conditioning. A building automation system is a linked assembly of controllers working together or under the direction of a central controller, and monitoring and controlling the operation of an HVAC system, a security system, or the like in one or more buildings to optimize the operation of the monitored system(s).
Presently HVAC systems have elements which are linked by wiring either directly, such as by twisted pair or cable, or which are linked indirectly, such as by power line carrier. Typical building automation systems and HVAC systems have elements which are linked by electrical connecting wires such as cable, twisted paired wires, or fiber optic cable. The cost of wiring and fiber optic cable is expensive both in installation and for material. Additionally, all such wiring must comply with local ordinances as well as national electrical codes. Furthermore, the use of permanent wiring limits both the initial design of the HVAC or building automation system, as well as subsequent improvements, modifications, and retrofits.
To date, no one has successfully implemented a wireless two-way HVAC or building automation system to link the system's controllers and sensors. To a limited extent some infrared transmissions are used to control some dampers. However, the infrared, light and ultrasonic transmission mediums are all subject to line of sight restrictions. Radio frequency transmissions, while not restricted to line of sight applications, have not been feasible for building automation systems and HVAC systems because radio frequency transmissions are subject to severe interference from building structures as well as from electronic devices. Additionally, FCC regulations limit the broadcasting of frequency ranges of radio frequency transmissions, which in turn further limits the applicability of radio frequency transmissions in building automation and HVAC systems.
Essentially, all known existing HVAC and building automation systems rely on a physical link between the major system elements. A wireless HVAC system and a wireless building automation system have heretofore been unknown.